1. Field of the Invention
The present invention pertains to an electrode assembly and a method of attaching one or more electrodes for measuring electrical signals generated by human organs, particularly in connection with electroencephalography.
2. Background
In the art of electroencephalography, and other techniques involving the measurement of electrical signals generated by human organs, one or more signal sensing devices or electrodes are placed in direct contact with the surface of the skin or other tissues for measuring electrical potentials generated by the organ.
In the art of electroencephalography, for example, various types of electrodes and methods of attachment to the scalp have been developed. One technique of attachment of a plurality of electrodes at various predetermined positions on the scalp utilizes a flexible cap made of a suitable fabric which must be worn by the patient during the monitoring process. My U.S. Pat. Nos. 4,085,739 and 4,323,076 disclose one preferred type of cap and an associated harness for use therewith. Although, the apparatus disclosed in the aforementioned patents is suitable for various measurement processes in clinical and hospital procedures there are many instances wherein it is desirable to measure the signals generated by the patient's brain or other organs over a relatively long period of time while permitting the patient to be ambulatory. Accordingly, the wearing of a cap or other structure for supporting the electrodes becomes uncomfortable or otherwise annoying to the patient.
However, the extremely low intensity of electrical signals generated by the brain and other organs requires techniques which minimize signal interference and which also require amplification of the signal detected by the electrodes. In this regard, it has been conventional practice to minimize the length of signal transmitting conductors or leads from the electrode to the signal amplification and/or recording equipment. In order to obtain meaningful electroencephalography devoid of extraneous signals or artifacts in ambulatory patients prior art practice in electroencephalography, has required the mounting of small preamplifier devices directly on the scalp closely adjacent to the electrodes to minimize electrode lead wire length. However, with the provision of several electrodes on the scalp, the addition of the preamplifier devices supported on the scalp closely adjacent to the electrodes is uncomfortable and interferes with normal activity of an ambulatory patient.
The mounting of preamplifier devices directly adjacent to the electrodes and the minimization of electrode lead length has been widely accepted as the only technique available to minimize so called artifacts or interfering signals generated during the recording of ambulatory electroencephalography data. Prior art arrangements of electrodes and preamplifiers have still not reduced signal interference to a degree which is desirable for providing reliable ambulatory electroencephalographs with the discovery of the present invention an improved electrode assembly and a technique for attaching a plurality of electrodes to the patient has been developed to provide more comfort without the generation of unwanted signals or interference.